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tion of the English Fleet that attacked and defeated the Spanish

Armada :

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As science developed so the divergence between the fighting ships and the trading ship became more marked, with the result that the Royal Navy at the outbreak of the war in 1914 consisted of battleships, cruisers, destroyers, submarines, minesweepers, and other special craft, and not one of these classes of vessels had any similarity to a merchant vessel. Nevertheless, the Royal Navy had to call upon the mercantile marine, not only for the transport of its own supplies and that of the Army, but also for fighting purposes. The submarine campaign called for an enormous number of vessel for purely fighting purposes, and at the end of the war there were some 3,500 auxiliary vessels converted from fishing and trading purposes.

In regard to personnel, there were enrolled in the Royal Navy three men drawn from volunteers or the mercantile marine to every man that the Navy proper employed at the outbreak of war. Without this great marine reserve to draw upon it is more than doubtful if British arms would have been successful either at the time of the Armada or during the Great War.

The lesson to be drawn from our experience, extending over many centuries is clear, and may be expressed as a necessary condition precedent to the acquisition and maintenance of sea-power, namely, sea-power must be built upon the broad basis of a great mercantile marine which in war-time co-operates with a powerful and efficient navy of specialised fighting vessels.

If this be true and if, so far as can be seen, it is probable that airpower will gradually replace sea-power, there will be the intermediate stage when the mastery of the seas depends upon securing the aerial advantage. During this intermediate stage the relative efficiency of the floating aircraft carrier and the airship-aeroplane is a very pertinent consideration. It seems logical that the cheaper, faster, and larger radius of action carrier must, in the end be adopted. And, added to these advantages is the fact that the more heavily armed surface vessels, submarines and mines which can attack the floating aircraft carrier are harmless against the flying carrier. However that may be, the fact remains that this latest three dimensional vessel can attack the battleship without having first to fight its way through the protecting screen of floating vessels. The deduction that must be drawn is vital.

The battleship to-day is the prop on which the cruisers, destroyers, minesweepers, armed merchantmen, &c., depend. Sometimes the

battlefleet comes out into the open and fights, as at Trafalgar; at other times it remains securely in its harbour, as was the case during the later period of the last war. But it is there, seen or unseen, and its actual or potential striking force is available; without it the whole naval power would fall like a pack of cards.

Obviously the patrol vessels are not concerned as to the actual form of prop so long as they can depend upon it. It may be a wooden prop as was the wooden three-decker, a wood and iron prop as the early ironclad, a steel prop as the modern dreadnought, or, as with the modern airship, an alloy prop.

If the above argument is followed to its logical conclusion, science may alter not only the form and construction of the prop, but its very characteristics.

At first sight the eventual substitution of the airship-aeroplane for the battleship appears visionary, but the facts from which deductions have been drawn are basic. It is not suggested that battleships can be given up to-day, but surely the lesson to be drawn is that airships will have a growing influence on naval strategy and tactics, and the final consideration is how can the British Empire lead in airship development.

The lesson history teaches in sea-power is that a fighting navy must be broadly based upon a mercantile marine, and in the early stages of development there was little difference between the fighter and the trader. Surely it is logical that the development of the air will follow upon the same lines. To start with, the airship will be merely a reconnaissance or auxiliary vessel, but as it develops in speed, endurance, and reliability, so will the differing requirements of war and trade necessitate a corresponding divergence of type. They will always have the same fundamental requirements in the way of bases, constructional facilities, trained crews, and the like. When that stage of development has been reached the mercantile airfleet will be able to form that great auxiliary force that can be called upon to assist in war.

If this reasoning is sound, the fact emerges that airships should be developed upon a commercial basis, and when the natural growth of scientific development renders a divergence of type between the reconnaissance or auxiliary vessel and the trading vessel desirable and necessary, then that is the moment for the commencement of a State service or Navy of specialised fighting airships.

In conclusion I must apologise for having stressed the naval and war uses of airships, when I am trying to develop upon a commercial and imperial basis but, as already explained, my hands have been tied by Mr. Lloyd George's decision, and I can only hope that the new Prime Minister will give more weight to the imperial and commercial sides than his predecessor.

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TUESDAY, 6th FEBRUARY.

AFTERNOON SESSION.

Sir HENRY P. MAYBURY, K.C.M.G., C.B., in the Chair.

The CHAIRMAN: My Lords and Gentlemen: It does not require any words from me to commend this all-important national subject to such a Conference as this. We had excellent papers read to us this Commander Burney.

morning, and we are to have equally good ones this afternoon. You will remember that the procedure is that the papers only are to be read to-day. Those that were read this morning will be discussed to-morrow morning, and those which are read this afternoon will, in like manner, be discussed to-morrow afternoon. If those who wish to take part in the discussion would kindly send up their names to the Secretary, either this afternoon or early to-morrow, it would be very convenient. I do not propose to keep you any longer, but I will call upon Air ViceMarshal Sir Geoffrey Salmond to read his paper.

THE PROGRESS OF RESEARCH AND EXPERIMENT.

Air Vice-Marshal Sir W. GEOFFREY H. SALMOND, K.C.M.G., C.B., D.S.O., Air Member for Supply and Research, Air Ministry.- Mr. Chairman, My Lords and Gentlemen: It is difficult in reviewing the year's work on Research to do adequate justice to the ardent hopes of research workers. You can never satisfy Research, for Research knows no horizon. It never finishes its journey, but it never relaxes its efforts to attain its journey's end.

During the year, however, much has been done, and I take this opportunity of thanking our scientists, workers and pilots, who have so loyally co-operated to produce the results achieved.

Perhaps I may be forgiven if I describe to you our organisation for research as I fear it is sometimes misunderstood. In the first place, there is the Air Ministry, charged with the general direction of research. The Air Ministry is advised by the Aeronautical Research Committee, either on the initiative of the Air Ministry or on the initiative of the Aeronautical Research Committee themselves, as to the problems which require to be solved or as to the methods by which they should be solved.

A representative of the Aeronautical Research Committee works in the Air Ministry and has direct access to me on all questions.

The Aeronautical Research Committee does invaluable work in investigating all sorts of problems, and is wonderfully assisted in its work by the National Physical Laboratory, the Department of Scientific and Industrial Research, and a whole body of scientists who give their services free to the nation, as well as by the great universities and consulting engineers.

These organisations deal with the theoretical solution of air problems in the domain of pure research. But research cannot stop here; its practical application has to be considered, and this portion of the work is carried out by the Royal Aircraft Establishment at Farnborough, various experimental stations, such as the Aircraft Experimental Establishment at Martlesham and the Marine and Armament Experimental Establishment, Isle of Grain, and by various joint committees of the Navy and Army.

A third organisation also exists, and that is the Aircraft and AeroEngine Constructors, who maintain most capable designing staffs who constantly bring forward solutions of problems which enable us to step forward.

I would be failing in my duty if I did not here acknowledge the debt this country owes to all these organisations, the joint efforts of which have undoubtedly brought our world position as regards research to what I confidently consider is a position second to none.

Now, work of great value has been carried out in regard to wing sections, with the object particularly of diminishing the length of the

run before the aeroplane leaves the ground and at the same time of reducing the landing speeds. The rate of "getting off" is an allimportant matter. At the present time the majority of machines have to carry an engine which must be run at maximum power for this purpose. Once the aircraft is in the air the economic and customary flying speeds are obtainable at three-quarters throttle, or even less. A certain amount of success has, I am glad to say, been met with in producing aeroplanes which are very much more efficient in "getting off" than their predecessors; if and when we have entirely achieved our object in this particular the aeroplane would be able to leave the ground with the engine at three-quarter throttle, so that, if desired, a smaller engine could be put in to run at the same power both for getting off" and for flying. This would result in a considerable saving of weight, economy in fuel, and a less expensive engine, all of which are invaluable from a civil point of view, and to a certain extent from a Service point of view. As regards civil aviation, it may be advisable to explore the possibility, after testing an engine at the makers' rating of, say, 500 h.p., of devising some means, such as choking the inlet, to make it not possible for the engine in ordinary running to give more than 450 h.p., with the material advantages of longer life and lower maintenance charges.

The problems of aeroplane design which we are particularly considering may be divided roughly into three categories: firstly, the single seater fighter, where the essential quality is high performance at altitude, say, above 20,000 feet. (The wing section for such a machine is an entirely different problem from that for a civil machine.) The next category-again a Service one-embraces a very large number of requirements, such, for example, as the amphibian, the boat machine, the reconnaissance machine, &c. The third category is the civil acroplane with which can be coupled the night bomber, troop carrier and ambulance machine.

With a single-seater fighter it is necessary to run the engine all out in order to get the requisite performance, and it must therefore be fitted with some means of maintaining power at altitude. This difficult problem is much in our minds, and is dealt with later.

As regards factors of safety, or load factors, it is a comparatively easy matter to stress a machine for normal flight and to determine the factor suitable to a given load, so as to produce freedom from breakdown. On the other hand, where stunting and aerobatics are indulged in the requirements are more stringent. Research has led us to adopt a factor of safety of 4 for civil machines where straight flying only is required; but for Service machines a figure of 7 is necessary. It is obvious that the more you can reduce this factor, having due regard to freedom from the likelihood of breakdown, the better, since this spells economy. In other words, no unnecessary weight must be taken into the air. The nature of the load distribution is of vital importance, and that this is so can scarcely be too strongly emphasised. It is, perhaps, a rather difficult matter with regard to civil machines, since you may, for example, have a carrying capacity of ten passengers and only take up three or four; where are these passengers to sit if correct stability is to be secured? This matter is being investigated and it is hoped shortly to lay down an authorised procedure. One line of investigation is to employ a small steelyard weighted to represent the weight of an empty machine. By hanging small weights on the yard representing the weights of baggage and passengers (i.e., the variable weight) the centre of gravity should be established.

Sir Geoffrey Salmond.

These quite general considerations of the strength of the aeroplane lead to the investigation of fundamentals, of which that on materials comes first; but research by itself on materials must be useless unless ease of production, and the possibility of bulk production, is ultimately ensured. These considerations need emphasis; it is on these lines that present research work is being conducted.

Materials with ostensibly miraculous properties are frequently submitted for consideration and sometimes they do possess some, at least, of the physical attributes claimed for them; but when regarding them from the production point of view they may be, and all too often are, prohibitive on account of cost, and more often than not are impossible on the bulk production basis: when considering bulk production there is one particular element which must not be lost sight of, namely, the time taken to produce.

Valuable work on steel, light alloys, and non-metallic materials has been carried out during the past year, thanks to the various panels of the Aeronautical Research Committee, the Department of Scientific and Industrial Research, the National Physical Laboratory, scientists, and the Royal Aircraft Establishment, Farnborough.

As regards fuel, very valuable research has been carried out and decided advances have been made during the year. Once it is realised that of the running cost of a machine one half may be due to fuel it is evident that research in this direction should be accelerated. For example, the present price of petrol is about 351. per ton, whereas crude oil can be obtained for about 41. per ton, and the same weight of either of these fuels will give approximately the same horse power. It is of great importance to civil aviation, and to the Royal Air Force, that encouragement should be given to schemes for the direct injection of fuel, both for economy and for doing away with both carburettor and magneto.

AERO ENGINES.

Although for service purposes engines giving as high as 1,000 h.p. and upwards are under development, for civil work there is little demand for an engine larger than from 400 to 450 h.p., and with this latter it is not desired, moreover, to run during level flying at a higher horse-power than about 350. Where one engine does not suffice the tendency will probably be to use three. With three engines the chance of a forced descent through engine trouble is comfortably remote.

As is well known, the full advantage of supercharged engines cannot be reaped unless a variable pitch propeller is provided. It is with such a combination that the highest altitudes of flying are obtainable It is an interesting point, however, that there is a quite separate demand for a variable pitch propeller for the purpose of civil aviation, where very high altitude flying is not customary. With the propeller of fixed pitch it is found that the tractive effort when "getting off is not in proportion to the torque being exerted by the engine, and that for full advantage of this torque to be obtained, it is necessary in aircraft as in motor cars for a variable velocity ratio to be employed. By this means the variable pitch propeller becomes equivalent to the gear box of a car and is used in the same way, namely, to enable the vehicle when starting from rest to attain the high acceleration.

Investigations are also being carried out with a view to introducing a variable gear in aero engines, in order to attack this problem.

Experiments are being made with an inverted form of the Napier Lion engine. The great merit that the inverted engine would have,

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